1. Field of the Invention
The present invention is related to testing apparatus and, more particularly, is directed towards a set of tools which may be adapted for testing the various components and interconnecting cables of standard telephone systems without requiring dismantling of same.
2. Description of the Prior Art
Standard modular telephone systems which utilize miniature jacks and plugs to interconnect the various components thereof are now widely utilized in the communication industry.
Such a system employs a telephone having a base, a handset, a receiver cord which is generally retractile and which interconnects the base and the handset, a wall-mounted terminal block, and a line cord which interconnects the terminal block with the telephone base.
The terminal block, which may be of a non-flush, flush or wall phone type, includes a special miniature jack which is identical to a second jack positioned in the rear of the base of the telephone. The line cord interconnecting the terminal block and base is terminated at both ends by a pair of identical miniature plugs which are sized to mate with the miniature jacks in the terminal block and telephone base. The miniature plugs include a quick connect-disconnect latch to greatly facilitate installation and separation of the line cord from the block and base. These miniature plugs and jacks include a plurality, usually four, wire terminals positioned therein for making electrical contact with correspondingly positioned wire terminals in the respective jack or plug. The advantages, features, and detailed structural design of such miniature jacks and mating plugs is typified in the Hardesty et al U.S. Pat. No. 3,699,498, issued Oct. 17, 1972 and assigned to Bell Telephone Laboratories Incorporated and Western Electric Company Incorporated.
Similarly, the retractile receiver cord is terminated at both ends by identical miniature plugs which are sized so as to mate with miniature jacks positioned respectively in the handset and telephone base. To avoid mistakes upon installation, the size of the jacks and plugs coupling the handset to the telephone base is usually different than the size of the jacks and plugs coupling the telephone base to the terminal block. Further, a third size and style of plugs and jacks are utilized in Trimline.RTM. telephones between the handset and the telephone base, as distinguished from the size of jacks and plugs presently being utilized between the handset and telephone base in standard desk telephones (Model 500), wall telephones (Model 554), and Princess.RTM. telephones. The model numbers and trademarks referred to herein are those which identify products of the Western Electric Company Incorporated of New York, N.Y., with which the devices of the present invention are particularly adapted to be utilized.
In the installation and repair of such modular telephone equipment, a serviceman must be able to identify the house cable, and check for dial tone, ground and battery. Such procedures generally require the use of a sounding device known as a "beeper", as well as a testset which consists simply of a hand-held receiver and transmitter having a pair of cables extending therefrom and terminating in alligator clips, for example.
Since the miniature jacks and plugs presently utilized in modular telephone systems are not amenable to direct connection of relatively large alligator clips used on such beepers and testsets, in order to perform such tests, the terminal block cover must be removed from the wall, or the telephone base must be dismantled, in order to obtain access to the exposed terminal wiring on the other side of the various jacks.
Dismantling of the terminal block covers or telephone bases is clearly time consuming. Further, as a result of the often fragile interconnection between the wiring cables and miniature jacks, the wiring is likely to be damaged when applying or removing the relatively bulky alligator clips.
It is clear, therefore, that it would be highly desirable if apparatus could be provided which would both avoid the time consuming necessity of dismantling the terminal blocks and telephone bases incident to the installation and/or repair of telephone sets and, at the same time, avoid altogether the possibility of damaging the internal wiring of such components. It is towards this end that the present invention is advanced.
Prior art United States patents in this general area of which I am aware include U.S. Pat. Nos. 2,249,153; 2,367,013; 2,648,052; 2,956,229; 3,600,678; 3,699,498; 3,711,611; 3,729,597; 3,736,387; 3,806,803; 3,870,836; 3,922,507; 3,976,849; 3,986,106; and 4,002,861.